Costa Milton Garcia, Dos Santos Sarah Marcilene Machado, de Mello Prado Renato, Palaretti Luiz Fabiano, de Cássia Piccolo Marisa, de Souza Júnior Jonas Pereira
Laboratory of Plant Nutrition, Department of Agricultural Sciences, São Paulo State University, Jaboticabal, São Paulo, Brazil.
Laboratory of Irrigation, Department of Rural Engineering, São Paulo State University, Jaboticabal, São Paulo, Brazil.
Front Plant Sci. 2022 Jul 29;13:949909. doi: 10.3389/fpls.2022.949909. eCollection 2022.
Studies with silicon (Si) in sugarcane indicate a greater response in productivity in plants under stress, and the underlying mechanisms of Si in the crop are poorly reported. In this context, the benefits of Si in the crop's stem production are expected to occur at the C:N:P stoichiometry level in plant tissues, benefiting plants with and without stress. However, the extension of this response may vary in different soils. Thus, this research aimed to evaluate if fertigation with Si modifies the C:N:P stoichiometry and if it can increase sugarcane's nutritional efficiency and vegetative and productive parameters. Therefore, three experiments were installed using pre-sprouted seedlings to cultivate sugarcane in tropical soils belonging to the Quartzarenic Neosol, Eutrophic Red Latosol, and Dystrophic Red Latosol classes. The treatments comprised a 2 × 2 factorial scheme in each soil. The first factor was composed without water restriction (water retention = 70%; AWD) and with water restriction (water retention = 35%; PWD). The second factor presented Si concentrations (0 mM and 1.8 mM) arranged in randomized blocks with five replications. Fertigation with Si increases the Si and P concentration, the C and N efficiency, the C:N ratio, and the dry mass production. However, it decreases the C and N concentration and the C:P, C:Si, and N:P ratios in sugarcane leaves and stems regardless of the water regime adopted in the three tropical soils. Cluster and principal components analysis indicated that the intensity of the beneficial effects of Si fertigation on sugarcane plants varies depending on the cultivation soil and water conditions. We found that Si can be used in sugarcane with and without water stress. It changes the C:N:P homeostasis enough to improve the nutritional efficiency of C, P, N, and, consequently, the dry mass accumulation on the stems, with variation in the different cultivated soils.
对甘蔗中硅（Si）的研究表明，胁迫条件下植物的生产力对硅的反应更大，而关于硅在作物中的潜在机制的报道较少。在这种情况下，预计硅对作物茎干生产的益处会在植物组织的碳：氮：磷化学计量水平上体现，无论有无胁迫，都会使植物受益。然而，这种反应的程度在不同土壤中可能会有所不同。因此，本研究旨在评估硅肥滴灌是否会改变碳：氮：磷化学计量，以及是否能提高甘蔗的营养效率以及营养和生产参数。为此，进行了三个实验，使用预发芽的幼苗在属于石英砂新成土、富营养红色富铁土和贫营养红色富铁土类别的热带土壤中种植甘蔗。每个土壤中的处理采用2×2析因设计。第一个因素包括无水分限制（保水率 = 70%；AWD）和有水分限制（保水率 = 35%；PWD）。第二个因素呈现硅浓度（0 mM和1.8 mM），以随机区组排列，重复五次。硅肥滴灌会提高硅和磷的浓度、碳和氮的效率、碳：氮比以及干物质产量。然而，无论在三种热带土壤中采用何种水分状况，它都会降低甘蔗叶片和茎干中的碳和氮浓度以及碳：磷、碳：硅和氮：磷比。聚类分析和主成分分析表明，硅肥滴灌对甘蔗植株有益影响的强度因种植土壤和水分条件而异。我们发现，无论有无水分胁迫，硅都可用于甘蔗。它足以改变碳：氮：磷的内稳态，从而提高碳、磷、氮的营养效率，并因此提高茎干上的干物质积累，不同种植土壤中存在差异。
